The present invention relates to a camera mount and, more particularly, the present invention relates to a ball and socket camera mount which may be used in conjunction with a robotic arm and head unit.
It is known in the prior art to use serial mechanisms, such as a pan and tilt mechanism for mounting a camera. Typically, pan and tilt mechanisms include a base, a rotatable pan platform and rotatable tilt bed for supporting and selectively orienting a camera in a desired direction. The pan platform is rotatably supported on the base about a pan axis and the tilt bed is rotatably supported on the pan. The tilt bed rotates about a tilt axis that is transverse to the pan axis. A pan motor drives the pan platform and a tilt motor drives the tilt bed in response to control signals that are provided to the unit.
Typical pan and tilt mechanisms require that the pan motor must drive the mass of the tilt motor, as well as the camera. The additional inertia required to drive the pan motor as a result of driving the weight of the tilt motor makes the pan tilt mechanism sluggish and unresponsive. In addition, the structure associated with the pan must also be driven by the pan motor, further decreasing the responsiveness of the camera mount. What is needed is a parallel mechanism for mounting a camera where the weight of the second motor does not have to be propelled by the first motor to orient the camera.
Disclosure of Invention
The present invention concerns a camera mount. The camera mount includes a socket, a ball, and at least one linkage. The socket includes an interior surface and an opening. The ball is positioned within a region defined by the interior surface of the socket. The ball includes an aperture for mounting a camera. The linkage is connected to the ball such that movement of the linkage causes rotation of the ball with respect to the socket.
In one embodiment, two linkages are comprised of first and second arms. The first and second arms are rotatably connected to the socket. The first arm includes a slot that is coupled to a post that extends from the ball. The post is constrained to motion along the first path defined by the slot in the first arm. The second arm includes a slot that is also coupled to the post extending from the ball. The post is constrained to motion along a second path that is defined by the second slot. Rotation of the first arm with respect to the socket moves the post along the second path. Rotation of the first arm moves the post extending from the ball along the first path. Controlled rotation of the first and second arms cause controlled rotation of the ball with respect to the socket.
In one embodiment, each arm includes a shaft portion and a coupling portion that includes the slot. Rotation of the shaft portion causes relative rotation between the coupling portion of the arm and the socket to move the ball with respect to the socket. In one embodiment, two camera mounts are coupled together for mounting stereo cameras.
One embodiment of the present invention concerns a robotic arm and head unit. The robotic arm and head unit includes a robotic arm, a robotic head, a camera mount, a camera, and a control. The robotic arm and robotic head are connected to a deck. The camera mount is connected to the robotic head. The camera mount includes a socket, a ball, and a linkage. The socket has an interior surface. The ball is positioned within a region defined by the interior surface and the socket. The ball includes an aperture for mounting a camera. The linkage is operably connected to the ball for rotating the ball in the socket. The camera is connected to the camera mount. The control moves the arm and head and positions the camera.
In one embodiment, a second camera mount is coupled to the first camera mount for mounting a stereo camera. In this embodiment, perception of an object by said cameras provides a signal to the control. The signal is processed by the control to determine the position of the object and the control causes the arm to move a tool attached to an end of the arm to the position of the sensed object. In one embodiment, the head is mounted to the deck by a robotic neck.
A camera is positioned with the camera mount of the present invention by mounting a camera in the aperture in the ball. One of the linkages operably connected to the ball are moved to rotate the ball within the interior region of the socket to position the camera.
In one embodiment, a shaft portion of a first linkage is rotated to cause rotation of an arm portion of the first linkage with respect to the socket. Rotation of the first arm portion moves a coupling post extending from the ball along a first path defined by a slot in a second arm portion of a second linkage to rotate the ball with respect to the socket. A shaft portion of a second linkage is rotated to cause rotation of a second arm portion of the second linkage with respect to the socket. Rotation of the second arm portion moves the coupling post along a second path that is defined by a slot in the first arm portion of the first linkage to move the ball with respect to the socket.